By Andrew Osborn
(Reuters) -The Russian military said on Tuesday it had routed militants who attacked a Russian border region with armoured vehicles the previous day, killing more than 70 "Ukrainian nationalists" and pushing the remainder back into Ukraine.
In what appeared to be one of the biggest incursions from Ukraine since the war began 15 months ago, two purported anti-Kremlin armed groups employing Russians based abroad said they were responsible for the attack in Russia's Belgorod region.
The Russian defence ministry, which blamed the Ukrainian authorities, said its forces had surrounded the enemy fighters and defeated them with "air strikes, artillery fire and active action by border units".
It said more than 70 Ukrainian fighters had been killed and four armoured vehicles and five pick-up trucks destroyed.
"The remnants of the nationalists were pushed back to Ukrainian territory, where they continued to be hit by gunfire until they were completely eliminated," the ministry added.
Belgorod regional Governor Vyacheslav Gladkov said a civilian had been killed by "the Ukrainian armed forces".
In a statement just after midnight, well after the military announced the end of the incursion, Gladkov reported a new incident, an explosive device dropped from a drone.
His post on Telegram messaging app said there were no injuries and showed a picture of a damaged car. A drone was later downed by anti-aircraft fire, he wrote.
Reuters was unable to verify any of the assertions.
One of the two fighting groups - the Russian Volunteer Corps (RVC) - said on social media: "One day we'll come to stay."
In a later statement, the group said it has suffered no losses in the incursion.
A second group, the Freedom of Russia Legion, said it had "demilitarised" a Russian motorised rifle company and destroyed armoured vehicles.
"...Putin's forces have not distinguished themselves with any successes in the past day," it said on social media. "...While they cowardly hide in the bushes, we will move forward to our goal -- the complete liberation of Russia!"
NOTHING TO DO WITH US, UKRAINE SAYS
Ukraine's government had said it was watching the situation but had "nothing to do with it". It said the same in March when one of the groups - which Moscow said consisted of far-right Russian extremists managed by Ukrainian intelligence - mounted an incursion into another border region.
Former President Dmitry Medvedev, now deputy chairman of Russia's Security Council, said Kyiv's denial was "lies" and that the attackers deserved to be exterminated "like rats".
Belgorod's Gladkov said he had cancelled a "counter-terrorism operation" that had since Monday allowed authorities to introduce restrictions on freedom of movement and communication.
Earlier on Tuesday, he had said security forces were still mopping up. He said an elderly woman had died while being evacuated and three people had been injured. Later he added, without providing detail, that a civilian had been killed.
The Freedom of Russia Legion is a Ukraine-based Russian militia led by Russian opposition figure Ilya Ponomaryov that says it is working to overthrow President Vladimir Putin.
Ponomaryov is wanted in Russia, where the authorities have accused him of spreading false information about the army and designated him a terrorist.
The RVC, which claimed responsibility for the March incursion, was founded in August by Ukraine-based Russian nationalist Denis Kapustin, and announced on May 17 that it was joining forces with the Legion.
Kremlin spokesman Dmitry Peskov said Russia was conducting its "special military operation" in Ukraine in part to ensure that such incidents could not be repeated.
Kyiv and its Western supporters say Russia's campaign is an unprovoked invasion to grab Ukrainian territory. Moscow says it is defending its own security from an ever-expanding NATO.
(Reporting by Reuters reporters; additional reporting by Lidia Kelly and Ron Popeski; writing by Andrew Osborn, Kevin Liffey; editing by Mark Heinrich, Cynthia Osterman and Grant McCool)